Elance’s look back at the year reveals that online hiring has soared more than 100 percent from 2010, and the number of professionals working on the site is up more than 120 percent. Cumulative earnings this year should surpass $500 million.

The state of [the] economy and unemployment is acting as a catalyst. It’s forcing a large portion of the workforce to look for alternatives. It’s forcing business to remain more flexible. But what we’re seeing is a change in how work is done and it’s similar to commerce. What caused e-commerce? Did the rise of e-commerce result from problems in the economy? Not really.

E-commerce started to be more effective in some categories than regular commerce, and I think that’s exactly what’s happening in the world of work. Working online in many ways is more efficient, more effective and more immediate than traditional employment. Businesses that use the flexible work model have distinct advantages over businesses that don’t, and there are some departments within these companies that have always used a flexible work model anyway. Creative departments, marketing departments [and] IT departments have always approached talent in a very flexible way on a project basis. They’re just doing it online now. So I don’t think we’re going back. I think this is really structural.

“The global demand for US talent has increased steadily over the past year and is set to grow even faster as online platforms like Elance break down global barriers,” says the release that goes along with today’s numbers. But Rosati is a little more understanding of those who feel the rise of these platforms is a mixed blessing for American workers.

When you create a global workplace and a global workforce, the dynamics are very different. Suddenly, you have a lot more competition cross-border. I know that is a very strong reality, and at the same time, there’s the other side of it, which is that for the first time, a very capable, talented, U.S.-based professional can access work and have clients all over the world, and we’re seeing exactly that on the U.S. platform. I feel that it’s an important side of what’s happening, because Americans have amazing talents. We’re seeing companies that may be hiring in some parts of the world for certain types of tasks, but for others, they love the opportunity to hire people based in the U.S.

I don’t doubt there are strong pressures when you compete with someone who is living in another part of the world. For example, it doesn’t even have to be someone who is in a lower-wage country. It could be simply someone who has access to public health insurance. So if you’re working in the U.S., and you have to pay for your own health insurance, you may be at a disadvantage to someone living in Norway who absolutely doesn’t because it’s all covered by the government. So that dynamic is definitely real and a challenging aspect of what is happening, but there are also many positive things.

You have to hand it to Rosati for acknowledging that, for all the psychological and lifestyle benefits of independent work, it does offload tasks and expenses ( (like obtaining health insurance, dealing with tax issues and building retirement savings) entirely onto the worker. Also to Elance’s credit is their partnership with eHealth to help U.S. community members compare health coverage options. “I wish I had the magic wand to address the problem, but I don’t,” says Rosati.

But health insurance isn’t the only external cost shifted from employer to worker in the paradigm shift these platforms are pushing. Though Elance clearly tries to make verifying work, billing for it and sorting out logistics as simple as possible with everything from an internal file management system to built-in virtual meeting facility, one can’t help but feel independent workers are more burdened with what Craig Lambert recently dubbed “shadow work” in the New York Times.

Lambert defines the term as “all the unpaid labor — including, for example, housework — done in a wage-based economy,” and muses that all of us, not just independent contractors, are being saddled with more and more of it in the name of corporate profits:

Science fiction novels of a half-century ago dramatized conflicts between humans and robots, asking if people were controlling their technologies, or if the machines were actually in charge. A few decades later, with the digital revolution in juggernaut mode, the verdict is in. The robots have won. Although the automatons were supposedly going to free people by taking on life’s menial, repetitive tasks, frequently, technological innovation actually offloads such jobs onto human beings.

The conventional wisdom is that America has become a “service economy,” but actually, in many sectors, “service” is disappearing. There was a time when a gas station attendant would routinely fill your tank and even check your oil and clean your windshield and rear window without charge, then settle your bill. Today, all those jobs have been transferred to the customer.

From automated airport check-in terminals and the near extinction of travel agents to understaffed retail outlets where we find our size ourselves, more and more places are shifting work, with all its attendant costs in time and energy, from companies to individuals, argues Lambert. In its well-intentioned way, Elance and its competitors appear to be doing the same.

Do the larger markets for our services and increase in lifestyle flexibility make up for these extra costs?